In order to provide a better user experience, more and more display products begin to integrate functions such as 3D display and dual view display. Currently, a liquid crystal grating is generally used to switch between 2D display and 3D display or between dual view display and non-dual-view display. However, the liquid crystal grating usually only has a single fixed grating pitch which cannot be switched or changed, so that a switch between the 3D display and the dual view display, a switch between two different 3D display effects and a switch between two different dual view display effects cannot be obtained.